/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_QUERIES;
import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractCollectionTester;
import com.google.common.collect.testing.MinimalCollection;
import com.google.common.collect.testing.WrongType;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;

import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.Iterator;

import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code removeAll} operations on a collection. Can't be invoked
 * directly; please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author George van den Driessche
 * @author Chris Povirk
 */
@SuppressWarnings("unchecked") // too many "unchecked generic array creations"
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class CollectionRemoveAllTester<E> extends AbstractCollectionTester<E>
{
    @CollectionFeature.Require(SUPPORTS_REMOVE)
    public void testRemoveAll_emptyCollection()
    {
        assertFalse(
                "removeAll(emptyCollection) should return false",
                collection.removeAll(MinimalCollection.of()));
        expectUnchanged();
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    public void testRemoveAll_nonePresent()
    {
        assertFalse(
                "removeAll(disjointCollection) should return false",
                collection.removeAll(MinimalCollection.of(e3())));
        expectUnchanged();
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_allPresent()
    {
        assertTrue(
                "removeAll(intersectingCollection) should return true",
                collection.removeAll(MinimalCollection.of(e0())));
        expectMissing(e0());
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_somePresent()
    {
        assertTrue(
                "removeAll(intersectingCollection) should return true",
                collection.removeAll(MinimalCollection.of(e0(), e3())));
        expectMissing(e0());
    }

    @CollectionFeature.Require({SUPPORTS_REMOVE, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
    @CollectionSize.Require(SEVERAL)
    public void testRemoveAllSomePresentConcurrentWithIteration()
    {
        try
        {
            Iterator<E> iterator = collection.iterator();
            assertTrue(collection.removeAll(MinimalCollection.of(e0(), e3())));
            iterator.next();
            fail("Expected ConcurrentModificationException");
        }
        catch (ConcurrentModificationException expected)
        {
            // success
        }
    }

    /**
     * Trigger the {@code other.size() >= this.size()} case in {@link AbstractSet#removeAll()}.
     */
    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_somePresentLargeCollectionToRemove()
    {
        assertTrue(
                "removeAll(largeIntersectingCollection) should return true",
                collection.removeAll(MinimalCollection.of(e0(), e0(), e0(), e3(), e3(), e3())));
        expectMissing(e0());
    }

    @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
    public void testRemoveAll_unsupportedEmptyCollection()
    {
        try
        {
            assertFalse(
                    "removeAll(emptyCollection) should return false or throw "
                            + "UnsupportedOperationException",
                    collection.removeAll(MinimalCollection.of()));
        }
        catch (UnsupportedOperationException tolerated)
        {
        }
        expectUnchanged();
    }

    @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
    public void testRemoveAll_unsupportedNonePresent()
    {
        try
        {
            assertFalse(
                    "removeAll(disjointCollection) should return false or throw "
                            + "UnsupportedOperationException",
                    collection.removeAll(MinimalCollection.of(e3())));
        }
        catch (UnsupportedOperationException tolerated)
        {
        }
        expectUnchanged();
    }

    @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_unsupportedPresent()
    {
        try
        {
            collection.removeAll(MinimalCollection.of(e0()));
            fail("removeAll(intersectingCollection) should throw UnsupportedOperationException");
        }
        catch (UnsupportedOperationException expected)
        {
        }
        expectUnchanged();
        assertTrue(collection.contains(e0()));
    }

    /*
     * AbstractCollection fails the removeAll(null) test when the subject
     * collection is empty, but we'd still like to test removeAll(null) when we
     * can. We split the test into empty and non-empty cases. This allows us to
     * suppress only the former.
     */

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(ZERO)
    public void testRemoveAll_nullCollectionReferenceEmptySubject()
    {
        try
        {
            collection.removeAll(null);
            // Returning successfully is not ideal, but tolerated.
        }
        catch (NullPointerException tolerated)
        {
        }
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_nullCollectionReferenceNonEmptySubject()
    {
        try
        {
            collection.removeAll(null);
            fail("removeAll(null) should throw NullPointerException");
        }
        catch (NullPointerException expected)
        {
        }
    }

    @CollectionFeature.Require(value = SUPPORTS_REMOVE, absent = ALLOWS_NULL_QUERIES)
    public void testRemoveAll_containsNullNo()
    {
        MinimalCollection<?> containsNull = MinimalCollection.of((Object) null);
        try
        {
            assertFalse(
                    "removeAll(containsNull) should return false or throw",
                    collection.removeAll(containsNull));
        }
        catch (NullPointerException tolerated)
        {
        }
        expectUnchanged();
    }

    @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_QUERIES})
    public void testRemoveAll_containsNullNoButAllowed()
    {
        MinimalCollection<?> containsNull = MinimalCollection.of((Object) null);
        assertFalse("removeAll(containsNull) should return false", collection.removeAll(containsNull));
        expectUnchanged();
    }

    @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
    @CollectionSize.Require(absent = ZERO)
    public void testRemoveAll_containsNullYes()
    {
        initCollectionWithNullElement();
        assertTrue(
                "removeAll(containsNull) should return true",
                collection.removeAll(Collections.singleton(null)));
        // TODO: make this work with MinimalCollection
    }

    @CollectionFeature.Require(SUPPORTS_REMOVE)
    public void testRemoveAll_containsWrongType()
    {
        try
        {
            assertFalse(
                    "removeAll(containsWrongType) should return false or throw",
                    collection.removeAll(MinimalCollection.of(WrongType.VALUE)));
        }
        catch (ClassCastException tolerated)
        {
        }
        expectUnchanged();
    }
}
